RE: I would like to build an archery backstop.Any suggestions?
Something else you might consider...in a lot of cities (if that is where you are at), at least here in KS, it is illegal to shoot bows in the city limits.
As far as the styrofoam I was talking about, we've not had any problems whatsoever with it at our archery club with relation to it "melting". I've shot 410 grain arrows at about 290 fps into it with no ill affects. Now, you wouldn't want to use it for broadheads, but it stops FT's just fine. It is not like the packing foam you get with your TV or something like that. It is very dense and made to protect and support a heavy load like a PTO shaft and such.